Scientists were able to determine the biological role geosmin — volatile compounds responsible for the smell of damp earth. It turned out that the Streptomyces (a genus of bacteria-actinomycetes possessing mycelium) distinguish it for the sake of attracting the spring tails: these arthropods feed on Streptomyces and spread their spores, drifting in the soil. This interaction promotes the formation of microbial communities in soil. The results of a study published in the journal Nature Microbiology.
Back in 1964 when the study of petrichor (the characteristic smell of earth after rain) opened geosmin — organic substance that makes the greatest contribution to its formation. Almost immediately it became clear that it is isolated soil streptomycetes secret, but why, no one knew.
An international group of scientists led by Paul Becher (Becher Paul) from the Swedish University of agriculture decided to investigate the biological role geosmin. They suggested that it can attract soil arthropods.
To test this hypothesis, the scientists laid in a tropical greenhouse network soil “traps” that are inhabited by colonies of Streptomyces species Streptomyces coelicolorand compared them to visit different groups of arthropods with their contact in the control traps. It was found that for the spring tails (in particular, Folsomia candida) traps with Streptomyces was much more attractive than the control (P < 0.001). For insects and arachnids such trends were not observed.